File system bugfixes

git-svn-id: http://h2database.googlecode.com/svn/trunk@5167 e6896862-9d19-0410-bfb3-e9fa5d50e656
MVTableEngine: test

git-svn-id: http://h2database.googlecode.com/svn/trunk@5168 e6896862-9d19-0410-bfb3-e9fa5d50e656